. >> iran's president, mahmoud ahmadinejad, shown here at natanz in 2008, blamed the cyber attack on enemies of the state and downplayed the damage. both the u.s. and israel maintain that it set back the iranian program by several years. what's impossible to know is how much damage the attackers might have inflicted if the virus had gone undetected and not been exposed by computer security companies trying to protect their customers. >> they planned to stay in that plant for many years and to do the whole attack in a completely covert manner, that anytime a centrifuge would break, the operators would think, "this is, again, a technical problem that we have experienced," for example, "because of poor quality of these centrifuges that we are using." >> we had a good idea that this was a blown operation, something that was never meant to be seen. it was never meant to come to the public's attention. >> you say blown, meaning? >> if you're running an operation like this to sabotage a uranium enrichment facility, you don't want the code uncovered. you want it kept secret, and you want it